Fang Zeng

Microstructure abnormalities in adolescents with internet addiction disorder.

Background Recent studies suggest that internet addiction disorder (IAD) is associated with structural abnormalities in brain gray matter. However, few studies have investigated the effects of internet addiction on the microstructural integrity of major neuronal fiber pathways, and almost no studies have assessed the microstructural changes with the duration of internet addiction. Methodology/Principal Findings We investigated the morphology of the brain in adolescents with IAD (N = 18) using an optimized voxel-based morphometry (VBM) technique, and studied the white matter fractional anisotropy (FA) changes using the diffusion tensor imaging (DTI) method, linking these brain structural measures to the duration of IAD. We provided evidences demonstrating the multiple structural changes of the brain in IAD subjects. VBM results indicated the decreased gray matter volume in the bilateral dorsolateral prefrontal cortex (DLPFC), the supplementary motor area (SMA), the orbitofrontal cortex (OFC), the cerebellum and the left rostral ACC (rACC). DTI analysis revealed the enhanced FA value of the left posterior limb of the internal capsule (PLIC) and reduced FA value in the white matter within the right parahippocampal gyrus (PHG). Gray matter volumes of the DLPFC, rACC, SMA, and white matter FA changes of the PLIC were significantly correlated with the duration of internet addiction in the adolescents with IAD. Conclusions Our results suggested that long-term internet addiction would result in brain structural alterations, which probably contributed to chronic dysfunction in subjects with IAD. The current study may shed further light on the potential brain effects of IAD.

Abnormal Resting Brain Activity in Patients With Functional Dyspepsia Is Related to Symptom Severity

BACKGROUND & AIMS Abnormal processing of visceral sensation at the level of the central nervous system is believed to be involved in functional dyspepsia. However, compared with studies of stimulation-related changes in brain activity, few studies have focused on resting brain activity, which also is important in pathogenesis. We mapped changes in resting brain glucometabolism of patients with functional dyspepsia, compared with healthy subjects, and attempted to correlate abnormal brain activity with symptom severity. METHODS We performed fluorodeoxyglucose positron emission tomography-computed tomography on 40 patients with functional dyspepsia and 20 healthy subjects who were in resting states. The symptom index of dyspepsia and the Nepean dyspepsia index were used to determine symptom severity. The positron emission tomography-computed tomography data were analyzed using statistical parametric mapping software. RESULTS Compared with healthy subjects, patients with functional dyspepsia had higher levels of glycometabolism in the bilateral insula, anterior cingulate cortex (ACC), middle cingulate cortex (MCC), cerebellum, thalamus, prefrontal cortex, precentral gyrus, postcentral gyrus, middle temporal gyrus, superior temporal gyrus, putamen, right parahippocampal gyrus, claustrum, and left precuneus (P < .001). The signal increase in the ACC, insula, thalamus, MCC, and cerebellum was correlated with symptom index of dyspepsia scores and Nepean dyspepsia index scores (P < .01). The glycometabolism in ACC, insula, thalamus, MCC, and cerebellum of patients with more severe functional dyspepsia was significantly higher than that of patients with less severe functional dyspepsia (P < .005). CONCLUSIONS In patients with functional dyspepsia, resting cerebral glycometabolism differs significantly from that of healthy subjects. The ACC, insula, thalamus, MCC, and cerebellum might be the key regions that determine the severity of symptoms.

Influence of Acupuncture Treatment on Cerebral Activity in Functional Dyspepsia Patients and Its Relationship With Efficacy

OBJECTIVES:Acupuncture is a commonly used therapy for treating functional dyspepsia (FD), although the mechanism remains unclear. The objectives of this study were to investigate the differences in cerebral glycometabolism changes evoked by acupuncture and sham acupuncture and to explore the possible correlations between brain responses and clinical efficacy.METHODS:In all, 72 FD patients were randomly assigned to receive either acupuncture or sham acupuncture treatment for 4 weeks. Ten patients in each group were randomly selected for fluorine-18 fluorodeoxyglucose positron emission tomography computed tomography scans to detect cerebral glycometabolism changes. The Nepean Dyspepsia Index (NDI) and Symptom Index of Dyspepsia (SID) were used to evaluate the therapeutic effect.RESULTS:(i) The clinical data showed that after treatment the decrease in SID score in the acupuncture group was significantly greater than that in the sham acupuncture group (P<0.05). The increase in NDI score between the two groups did not differ (P>0.05), and only the improvement in NDI score in the acupuncture group was clinically significant. (ii) The neuroimaging data indicated that after treatment the acupuncture group showed extensive deactivation in cerebral activities compared with the sham acupuncture group. In the acupuncture group, the deactivations of the brainstem, anterior cingulate cortex (ACC), insula, thalamus, and hypothalamus were nearly all related to the decrease in SID score and the increase in NDI score (P<0.05, corrected). In the sham acupuncture group, the deactivations of the brainstem and thalamus tended to be associated with the increase in NDI score (P<0.1, corrected).CONCLUSIONS:Acupuncture and sham acupuncture have relatively different clinical efficacy and brain responses. Acupuncture treatment more significantly improves the symptoms and quality of life of FD patients. The more remarkable modulation on the homeostatic afferent network, including the insula, ACC, and hypothalamus, might be the specific mechanism of acupuncture.

A PET-CT study on the specificity of acupoints through acupuncture treatment in migraine patients

BackgroundIn the field of acupuncture research, the topic of acupoint specificity has received increasing attention, but no unified conclusion has been reached on whether or not acupoint specificity exists. Furthermore, the majority of previous acupuncture neuroimaging studies have been performed using healthy subjects. In this study, patients with migraine were used to investigate acupoint specificity.MethodsThirty patients with migraine were enrolled and randomized into three groups: Traditional Acupuncture Group (TAG), Control Acupuncture Group (CAG), and Migraine Group (MG). The TAG was treated by acupuncture stimulation at Waiguan (TE5), Yang Lingquan (GB34), and Fengchi (GB20). The CAG was treated at Touwei (ST8), Pianli (LI6), and Zusanli (ST36). The MG received no treatment. Positron emission tomography with computed tomography (PET-CT) was used to test for differences in brain activation between the TAG and CAG versus MG, respectively.ResultsTraditional acupuncture treatment was more effective for pain reduction than control acupuncture treatment. The TAG showed higher brain metabolism than the MG in the middle temporal cortex (MTC), orbital frontal cortex (OFC), insula, middle frontal gyrus, angular gyrus, post-cingulate cortex (PCC), the precuneus, and the middle cingulate cortex (MCC). Metabolism decreased in the parahippocampus, hippocampus, fusiform gyrus, postcentral gyrus, and cerebellum in the TAG compared with the MG. In the CAG, metabolism increased compared with the MG in the MTC, supratemporal gyrus, supramarginal gyrus, and MCC, whereas metabolism decreased in the cerebellum.ConclusionsAcupuncture stimulation of different points on similar body regions in migraine patients reduced pain and induced different levels of cerebral glucose metabolism in pain-related brain regions. These findings may support the functional specificity of migraine- treatment-related acupoint.Trial registrationThe number of our clinical trial registration is: ChiCTR-TRC-11001813, and the protocol and inclusion criteria have already been registered as ChiCTR-TRC-11001813.

White-Matter Microstructural Changes in Functional Dyspepsia: A Diffusion Tensor Imaging Study

OBJECTIVES:Recent neuroimaging studies have identified brain microstructural changes in patients with functional gastrointestinal disorders, especially in irritable bowel syndrome. However, whether the microstructure is changed in patients with postprandial distress syndrome (PDS) remains elusive. Therefore, the present study was aimed to examine the white-matter (WM) microstructural changes in patients with PDS.METHODS:Diffusion tensor imaging (DTI) was performed on 36 PDS patients recruited according to the Rome III criteria and 36 healthy controls. Tract-based spatial statistics were adopted to examine the between-group differences in DTI measures including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, and radial diffusivity (RD). The correlations between DTI measures and clinical variables were evaluated using a non-parametric permutation-based test. Multiple comparisons were corrected using the threshold-free cluster enhancement method.RESULTS:The patient group showed increased FA along with reduced MD and RD in multiple WM tracts, including the corona radiata, internal capsule, posterior thalamic radiation, corpus callosum, external capsule, sagittal stratum, and superior longitudinal fasciculus (P<0.05, corrected). The inclusion of anxiety and depression as covariates abolished the between-group difference in these tracts with the exception of the corona radiata. The DTI measures were not found to be correlated with the severity of symptoms or the duration of disease (P>0.05, corrected).CONCLUSIONS:Our findings have provided preliminary evidence of WM microstructural changes in patients with PDS. Part of the changes could be accounted for by a higher level of psychosocial distress in the patient group.

Impact of Brain-Derived Neurotrophic Factor Val66Met Polymorphism on Cortical Thickness and Voxel-Based Morphometry in Healthy Chinese Young Adults

Background Following voxel-based morphometry (VBM), brain-derived neurotrophic factor (BDNF) Val66Met polymorphism (rs6265) has been shown to affect human brain morphology in Caucasians. However, little is known about the specific role of the Met/Met genotype on brain structure. Moreover, the relationship between BDNF Val66Met polymorphism and Chinese brain morphology has not been studied. Methodology/Principal Findings The present study investigated brain structural differences among three genotypes of BDNF (rs6265) for the first time in healthy young Chinese adults via cortical thickness analysis and VBM. Brain differences in Met carriers using another grouping method (combining Val/Met and Met/Met genotypes into a group of Met carriers as in most previous studies) were also investigated using VBM. Dual-approach analysis revealed less gray matter (GM) in the frontal, temporal, cingulate and insular cortices in the Met/Met group compared with the Val/Val group (corrected, P<0.05). Areas with less GM in the Val/Met group were included in the Met/Met group. VBM differences in Met carriers were only found in the middle cingulate cortex. Conclusions/Significance The current results indicated a unique pattern of brain morphologic differences caused by BDNF (rs6265) in young Chinese adults, in which the Met/Met genotype markedly affected the frontal, temporal, cingulate, and insular regions. The grouping method with Met carriers was not suitable to detect the genetic effect of BDNF Val66Met polymorphism on brain morphology, at least in the Chinese population, because it may hide some specific roles of Met/Met and Val/Met genotypes on brain structure.

Altered periaqueductal gray resting state functional connectivity in migraine and the modulation effect of treatment

The aims of this study were to 1) compare resting state functional connectivity (rs-fc) of the periaqueductal gray (PAG), a key region in the descending pain modulatory system (DPMS) between migraine without aura (MwoA) patients and healthy controls (HC), and 2) investigate how an effective treatment can influence the PAG rs-fc in MwoA patients. One hundred MwoA patients and forty-six matched HC were recruited. Patients were randomized to verum acupuncture, sham acupuncture, and waiting list groups. Resting state fMRI data were collected and seed based functional connectivity analysis was applied. Compared with HC, MwoA patients showed reduced rs-fc between the PAG and rostral anterior cingulate cortex/medial prefrontal cortex (rACC/mPFC), key regions in the DPMS and other pain related brain regions. The reduced rs-fc between the PAG and rACC/mPFC was associated with increased migraine headache intensity at the baseline. After treatments, rs-fc between the PAG and the rACC in MwoA patients significantly increased. The changes of rs-fc among the PAG, rACC and ventral striatum were significantly associated with headache intensity improvement. Impairment of the DPMS is involved in the neural pathophysiology of migraines. Impaired DPMS in migraine patients can be normalized after effective treatment.

Brain areas involved in acupuncture treatment on functional dyspepsia patients: a PET-CT study.

Neuroimaging studies on brain responses to acupuncture stimulations have received considerable attention recently. The majority of these studies are centered on healthy controls (HC) and neuropathy, while little work has addressed other disorders. This study aimed to investigate the influence of acupuncture stimulations on brain activities in functional dyspepsia (FD) patients. Eight FD patients and eight healthy controls (HC) were involved in this study. Each HC received an 18F-FDG PET-CT scan at baseline, while each patient received scans at baseline and after acupuncture stimulations. Manual acupuncture stimulations were performed at ST34 (Liangqiu), ST36 (Zusanli), ST40 (Fenglong) and ST42 (Chongyang) in FD patients. The images were analyzed with the Statistical Parametric Mapping software 2.0. Compared to HC, the FD patients showed a lower glycometabolism in the right orbital gyrus, the left caudate tail and the cingulate gyrus, and a higher glycometabolism in the left inferior temporal gyrus (p<0.005). After acupuncture stimulations, the FD patients showed a glycometabolism decrease in the postcentral gyrus and the cerebella, and an increase in the visual-related cortices(p<0.005). The results suggest that the anterior cingulate cortex, the prefrontal cortices and the caudate tail involve in processing gastric perceptions in FD patients and that the deactivation of the primary somatosensory area and the cerebella is contributable to acupuncture stimulation, while activation of the visual-related cortex is a response to pain or acupoint actions.

Identifying Neural Patterns of Functional Dyspepsia Using Multivariate Pattern Analysis: A Resting-State fMRI Study

Background Previous imaging studies on functional dyspepsia (FD) have focused on abnormal brain functions during special tasks, while few studies concentrated on the resting-state abnormalities of FD patients, which might be potentially valuable to provide us with direct information about the neural basis of FD. The main purpose of the current study was thereby to characterize the distinct patterns of resting-state function between FD patients and healthy controls (HCs). Methodology/Principal Findings Thirty FD patients and thirty HCs were enrolled and experienced 5-mintue resting-state scanning. Based on the support vector machine (SVM), we applied multivariate pattern analysis (MVPA) to investigate the differences of resting-state function mapped by regional homogeneity (ReHo). A classifier was designed by using the principal component analysis and the linear SVM. Permutation test was then employed to identify the significant contribution to the final discrimination. The results displayed that the mean classifier accuracy was 86.67%, and highly discriminative brain regions mainly included the prefrontal cortex (PFC), orbitofrontal cortex (OFC), supplementary motor area (SMA), temporal pole (TP), insula, anterior/middle cingulate cortex (ACC/MCC), thalamus, hippocampus (HIPP)/parahippocamus (ParaHIPP) and cerebellum. Correlation analysis revealed significant correlations between ReHo values in certain regions of interest (ROI) and the FD symptom severity and/or duration, including the positive correlations between the dmPFC, pACC and the symptom severity; whereas, the positive correlations between the MCC, OFC, insula, TP and FD duration. Conclusions These findings indicated that significantly distinct patterns existed between FD patients and HCs during the resting-state, which could expand our understanding of the neural basis of FD. Meanwhile, our results possibly showed potential feasibility of functional magnetic resonance imaging diagnostic assay for FD.

Alterations of the default mode network in functional dyspepsia patients: a resting-state fmri study

Increasing brain imaging studies have emphasized the role of regional brain activity abnormalities in functional dyspepsia (FD) during the resting state. The goal of this study was to investigate the default mode network (DMN) in FD patients and healthy controls (HCs).